Abstract
Aspirin can be tabletted by itself but the tablet does not disintegrate because the contact angle of Aspirin is over 90° and water cannot penetrate inside the tablet. When Aspirin is tabletted with starch, whose contact angle is 80-85°, water will penetrate through a canal made of starch grains and cause disintegration of such a tablet. The use of talc is known to cause poor disintegration and this is primarily due to the fact that talc does not adhese to starch or crystals, forming aggregate of talc itself and because its contact angle is over 90°, preventing penetration of water.
